The heating and cooling profiles experienced during laser additive manufacturing results in residual stresses build up in the component. Therefore, it is necessary to perform post build stress relieving towards the retention and improvement of the mechanical properties. However the thermal treatments for conventional manufacturing do not seem to completely accommodate these rapid heating and cooling cycles of laser processing techniques such as powder bed fusion. Characterizations such as density measurements on the samples were performed employing the Archimedes principle; hardness testing was performed on the Zwick micro/macro (Hv) hardness tester, SEM and Electron backscatter diffraction (EBSD). Fracture toughness and crack growth was conducted on a fatigue crack machine. All characterization was done after stress relieving of Selective Laser Melting (SLM) produced samples at 300 °C for 2 hrs was performed in a furnace. The mechanical properties appear to be rather compromised instead of being enhanced desirably. As-built SLM produced tensile specimens built in different directions exhibited significantly favorable mechanical properties. However, post stress relieve thermal treatment technique deteriorated the strength while increasing the ductility significantly. Nonetheless, fatigue crack growth and fracture toughness illustrated positive outcome in terms of fatigue life on SLM produced AlSi10Mg components in application.

The AlSi10Mg alloy is known for its castability, corrosion resistance, high heat conductivity, low weight and good weldability. Applications of the aluminium alloy components includes heat exchangers that are subjected to high temperatures and corrosive environments. The production process of AlSi10Mg alloy using selective laser melting has been extensively explored because of its hypoeutectic composition of Al and Si. However, it has been observed that stress relieve has a negative consequence on tensile properties of SLM built samples, while retaining and improving ductility. The thermal behaviour of AlSi10Mg alloy fabricated by selective laser melting with the specimen heat treated at 300°C for 2 hours investigated in this work. The specimens exhibited mass gain during the thermalgravimetric analysis as a result of the precence of oxygen as one of the elements present as detected by the elemental analysis. The fatigue results post thermal treatment demonstrated improved fatigue resistance qualities comparable to die-casted AlSi10Mg.

Titanium carbide has developed into an exceptional reinforcement contender in Aluminium Matrix Composites (AMCs) because of its greater characteristics such as elevated hardness, elevated elastic modulus, low heat conductivity, and constancy at moderately elevated temperatures. Furthermore, it is consequently selected as the reinforcing segment in AMCs because of its good thermodynamic and wettability stability inside the aluminium melt pool. In this work, titanium carbide powder was mixed to distinguish AlSi₁₀Mg strengthening by the additive manufacturing (AM) process in the category of powder bed identified as Powder Bed Fusion (PBF). The objective of the study was to have homogeneously mixed powders for processing on the reinforcement of AlSi₁₀Mg with TiC. Different characterisation procedures were carried out, such as scanning electron microscope energy dispersive X-ray spectroscopy (SEM-EDS), pycnometry, and thermogravimetric analysis (TGA). The advancement of powder density from 2.65 to 2.72 g/cm³ and surface area from 0.02 to 0.14 m²/g was accomplished. The modelling findings concurred that the addition of Ti and C increases the density of the alloy, with Ti contributing more to AlSi than C. It was deduced that with Ti and C added to the system, the bulk modulus increases, with Al₆Si₈TiC having the largest value of 80.34 GPa.